NAD+, NMN and NR: what is the difference?

Three names, three chemical identities

NAD stands for nicotinamide adenine dinucleotide. NAD+ is the oxidised form; NADH is the reduced form. These forms participate in electron-transfer reactions. NAD+ is also used as a substrate by enzymes, so the term covers more than a single function.

NMN, nicotinamide mononucleotide, is a nucleotide. NR, nicotinamide riboside, is a nucleoside. The phosphate group distinguishes NMN from NR. This distinction explains why the names cannot be used as synonyms, even though both compounds are described as NAD+ precursors.

A reaction pathway is not a measure of efficacy

A known reaction pathway runs from NR through NMN to NAD+. NR kinase enzymes can form NMN from NR, which can then be converted to NAD+. This is a biochemical connection between the molecules, rather than a ranking of them as products.

In 2016, Trammell and colleagues investigated how NR affected NAD-related metabolites in mice and humans. Their work provided information about metabolism and availability. These measurements must be distinguished from studies examining disease, function or longevity.

A change in a blood sample also does not necessarily indicate the same change in every tissue. When an article states that NAD+ increased, it should therefore specify where and how it was measured.

NR: distinguish biomarkers from clinical measures

In 2018, Martens and colleagues published a randomised, double-blind, placebo-controlled crossover study in healthy middle-aged and older adults. The study showed higher NAD+ levels in the blood cells examined after NR. The short study also provided preliminary observations on physiological measures, which the authors considered worthy of further investigation.

That same year, Dollerup and colleagues investigated NR in men with obesity in a randomised, placebo-controlled study. They found no improvement in insulin sensitivity or several of the metabolic measures examined. This study shows why growing interest in NAD metabolism cannot be translated into a general claim of metabolic benefit.

Results must be read in the context of the participant group and endpoint. Two studies examining NR do not necessarily measure the same outcome or answer questions about the same population.

NMN: a specific finding in a particular group

In 2021, Yoshino and colleagues published a ten-week randomised, double-blind, placebo-controlled study in postmenopausal women with prediabetes and overweight or obesity. The study found improved insulin-stimulated glucose uptake and investigated signalling pathways in skeletal muscle.

This finding applies to the group studied and the specific measures. It does not by itself establish that NMN extends life, treats all forms of metabolic disease or produces the same result in healthy men and younger women.

The study compared NMN with placebo. It was not a direct comparison of NMN, NR and NAD+. Setting the result against a separate NR study and declaring a winner would mix different participant groups and experimental designs.

What a comparison needs to document

A scientific comparison should specify which molecule was investigated, which formulation was used, who or what was studied and which endpoint was measured. It must also make clear whether the conclusion concerns a biomarker, a functional test or a clinical outcome.

Short-term tolerability in one study does not establish long-term safety for all groups. A finding for an investigational product also does not document the composition of another supplier's raw material. Chemical analysis and clinical research answer different questions.

For a particular research material, identity and batch documentation must be assessed separately. Contact ArcticAmino for a copy of the batch's certificate of analysis before ordering. That report is not a clinical study or confirmation of a health effect.